Numerous solid composition which generate hydrogen by combustion are known, in particular for producing hydrogen intended to act as fuel in chemical lasers.
Patent U.S. Pat. No. 3,948,699 discloses solid compositions which generate hydrogen by combustion composed of a mixture of alkali metal borohydride, for example sodium borohydride NaBH4, with a metal oxide, for example iron oxide Fe2O3.
However, the yields by mass of hydrogen produced are low, less than 5%, expressed by weight of hydrogen obtained with respect to the total weight of the composition.
Patent U.S. Pat. No. 4,064,225 discloses other solid compositions which generate hydrogen by combustion composed of a mixture of alkali metal borohydride, for example sodium borohydride, with ammonium sulphate (NH4)2SO4 or ammonium dichromate (NH4)2Cr2O7.
The yields by mass are slightly higher, of the order of 6%.
Such hydrogen yields, less than or in the vicinity of 5%, prove in practice to be inadequate, in particular when miniaturization of systems is desired, for example when it is desired to replace the batteries of portable electronic systems, such as telephones and computers, with miniature hydrogen fuel cells.